On Dec. 9, Israel, Jordan and the Palestinian Authoritysigned a major deal that calls for the construction of a large desalination plant in Jordan that would take billions of gallons of water from the Dead Sea and convert it to clean drinking water—water that would be shared by Jordan and Israel. The leftover brine water would be pumped via a new, 100-mile pipeline and discharged back into the Dead Sea, the massive lake that has water 10 times as salty as that found in the oceans. The deal also calls for Israel to increase the amount of water it sells to the parched Palestinian Authority by as much as 30 million cu. meters. Silvan Shalom, the Israeli water and energy minister, called the agreement “of the highest diplomatic, economic, environmental and strategic importance.”

My colleague Karl Vick in Jerusalem has more on the deal, which environmentalists have a number of qualms about. The Dead Sea has been shrinking for years, with the lake’s surface area declining by 20% over the past two decades as water from the River Jordan, which feeds into the Dead Sea, has been appropriated for farming and domestic use in Israel, Syria and Jordan. The deal itself looks to be much smaller than a mega-project that has been on the drawing board for almost 20 years.

But even if the Dead Sea deal is less than historic, it’s still a deal, hammered out by entities that usually have a hard time even speaking to each other. And it’s a reminder that contrary to the much-repeated phrase that “the next world war will be fought over water,” similar deals tend to be the rule with international disputes over water, not the exception. Far from being a source of violent conflict—like religion or oil—water is something that even bitter rivals can usually sit down and discuss, however reluctantly.

I don’t blame you if you don’t believe me. The idea that water is a limited resource that will inevitably be the source of conflict in arid regions of the world is considered a given in many security, foreign policy and environmental circles. Just see this piece, or this one, or that one. Or this piece, or this one, or that one. (And those are just from 2013.) Water wars were even the subject of the 2008 James Bond film Quantum of Solace—the one with the eco-villain named Greene who was going to corner the Bolivian market on water, which I have to say, is pretty dull compared to irradiating the gold in Fort Knox (Goldfinger) or flooding all of Silicon Valley (A View to a Kill). Even Mark Twain, referring to disputes between Western U.S. states over the Colorado River, memorably said that “whiskey is for drinking. Water is for fightin’ over.”

But when it comes to actual armed conflict—as opposed to wars of words—I’m sorry to say that Mr. Twain has it wrong. That’s what science journalist Helen Barnaby discovered when she began work a number of years ago on a proposed book about water wars. In the course of her research, Barnaby discovered that there hasn’t been an actual war between two nations over water for about 4,500 years, back when Lagash and Umma, two Mesopotamian city-states located in what is now southern Iraq, took up arms over boundary canals. Sandra Postel and Aaron Wolf found that between the years of 805 and 1984, countries signed more than 3,600 water-related treaties. Their analysis of 1,831 international water-related treaties over the second half of the 20th century found that two-thirds of the encounters were of a cooperative nature. India and Pakistan have abided by the World Bank-arbitrated Indus Waters Treaty since 1960, and none of the three wars the bitter rivals have fought were caused by water disputes. Even as Palestinians and Israelis kill each other, water professionals on both sides interact through the Joint Water Committee, established by the Oslo-II Accords in 1995.

Drawing on research from Tony Allan at the School of Oriental and African Studies in London and the late Gideon Fishelson from Tel Aviv University, Barnaby notes that much of the water we consume is actually “embedded” in the goods we consume, like fruits and vegetables. (This is also known as “virtual water.”) While temperate countries like the U.S. can produce more than enough water to meet their population’s needs—about 1 cu. meter per year for drinking, 100 cu. meters for washing and cleaning, and 1,000 cu. meters a year to grow food—arid countries like Israel have long since outgrown their water supplies, as Barnaby writes:

Ten million people now live between the Jordan River and the Mediterranean Sea. If they were to be self-sufficient in food, they would need ten billion cu. meters of water per year. As it is, they have only about one-third of that: enough to grow 15-20% of their food. They import the rest in the form of food.

More virtual water flows into the Middle East each year in the form of imported grain that flows down the Nile to farmers in Egypt. Nations cooperate on water, through trade and treaties, because they have no other choice. And that’s a good thing, because it means that water is one area where even fractious countries are forced by their own needs to negotiate with each other. They may threaten war over water, but they almost never resort to it.

None of this is to say that water scarcity isn’t a major global problem now and won’t be a bigger one in the future, as global population increases—especially in already arid countries in the Middle East and sub-Saharan Africa—and climate change alters hydrological patterns. Peter Gleick at the Pacific Institute for Studies in Development, Environment and Security complied a list of scores of conflict that occurred over water, going all the way back to ancient Sumerian legend. But the violence in the vast majority of these cases is relatively contained, and usually civil—within a country, rather than between nation-states. Which does point to a problem. The severity of armed conflict between nation-states has declined sharply in recent decades, even with the U.S. invasions of Iraq and Afghanistan. But civil conflict is still a major problem, as the ongoing civil war in Syria demonstrates, and it’s one that will likely be worsened thanks to climate change and dwindling resources—including water.

The belief that, as Barnaby wrote, “cooperation is the dominant response to shared water resources,” depends on the existence of relatively stable nation-states capable of safely negotiating and trading with each other. In a hot and crowded future, there’s no guarantee that already troubled countries won’t eventually fall apart under the stress. And if that happens, all bets are off.

"Because of its reliance on livestock agriculture, Israel's economy depends heavily on groundwater use. You can't make the desert bloom through sheer hard work; it requires water. Today Israel is heavily dependent on water from the West Bank, and the Israeli press is full of talk of retaining the West Bank in order to protect water supplies from encroaching Arab wells. One analyst gloomily concludes that the water in the West Bank region--which the Israelis captured from the Arabs in the 1967 war--is 'fast becoming the most ominous obstacle to any peaceful settlement in the region.'"

Growth over the past 4,500 years has been essentially linear and slow. It is only in the past 100 years or so that we have entered a new consumption epoch - exponential increases in consumption of water, land, energy, etc. History may not serve to point the way to how we will behave in our exponentially dwindling resource future.